A lot of people because there is no right to read "220V AC Cooling Fan" parameters, resulting in a lot of parameters to meet the demand as caused by overheating. Heat issues unresolved. Here we teach the DC fan selection parameters. The first is DC fan size. "220V AC Cooling Fan" is pretty much the size. Generally based on mm units, usually the length and width 25MM to 120MM. There is a big point of the circle, is 172MM diameter. Through blade hydrodynamics and diversion mechanism to optimize the design, so that the maximum pressure "220V AC Cooling Fan" of the air flow performance of up to 62 mm-Aq, the largest amount of wind up to 81 CFM. In the high-order customers required system performance, but also a substantial override the client system's impedance setting performance goals required by 20%, while the maximum power consumption was estimated target customers better than 20%. Achieve true high-efficiency, environmental protection and energy saving!